Title of Invention	ONE-HAND ACTUATED, SELF-CLOSING PLIERS
Abstract	The spring mechanism (12) of a one-hand actuated pliers consists of a spring (14) supported on both handles (2, 3), which is designed in such a way that the handles (2, 3) are separated at a distance from each other by rotating the handle (3) and wherein the movable handle (3) of the pliers can be moved by the spring to the widest open position of the jaws by rotating said handle (3), wherein a rotation support of the spring (14) is configured on one side of the handle (2) and the spring (14) rests on said side against a rotational stop (19) formed on the handle (2) when it is not actuated. When the movable handle (3) of the pliers is displaced to a closing position of the jaws in which a workpiece is grasped, the spring (14) is released from the rotational stop only if force is exerted when the cheeks of the jaws (5, 6) are grasping the workpiece.

Title of Invention

ONE-HAND ACTUATED, SELF-CLOSING PLIERS

Abstract

The spring mechanism (12) of a one-hand actuated pliers consists of a spring (14) supported on both handles (2, 3), which is designed in such a way that the handles (2, 3) are separated at a distance from each other by rotating the handle (3) and wherein the movable handle (3) of the pliers can be moved by the spring to the widest open position of the jaws by rotating said handle (3), wherein a rotation support of the spring (14) is configured on one side of the handle (2) and the spring (14) rests on said side against a rotational stop (19) formed on the handle (2) when it is not actuated. When the movable handle (3) of the pliers is displaced to a closing position of the jaws in which a workpiece is grasped, the spring (14) is released from the rotational stop only if force is exerted when the cheeks of the jaws (5, 6) are grasping the workpiece.

Full Text	FORM 2 THE PATENTS ACT 1970 [39 of 1970] & THE PATENTS RULES 2003 COMPLETE SPECIFICATION [Section 10; rule 13] "ONE-HAND ACTUATED, SELF-CLOSING PLIERS" KNIPEX-WERK C. GUSTAV PUTSCH, of Oberkamper Strasse 13, D-42349 Wuppertal, Germany, The following specification particularly describes and ascertains the nature of the invention, and the manner in which it is to be performed:- WO 00/13856 PCT/EP99/06560 Self-closing pliers which can be actuated by one hand The invention relates to a self-closing pliers which can be actuated by one hand, having two pliers legs which are connected to one another by means of an articulation bolt, it being the case that a pliers mouth is formed above the crossover region of the pliers legs and handle sections are formed on the pliers legs below the crossover region, it being the case that one of the pliers legs, which can be adjusted relative to the other pliers leg in the crossover region in order to change the size of the pliers mouth, has a free space which is penetrated by the other pliers leg, or the non-adjustable pliers leg is penetrated by the adjustable pliers leg, and it being the case that, furthermore, the pliers legs are connected via a regulating element and a spring drive, which biasses the pliers mouth into an open position, which open position is produced automatically under ing loading once the handle sections have been relieved of loading, it being the case that, moreover, in a first movement section of the spring drive, the pliers-mouth jaws move towards one another and, in a second movement section, a catch of the articulation bolt engages in a latching toothing formation, whereupon forced rotation of the movable pliers-mouth jaw about the articulation bolt can be carried out. It is an object of the invention to improve pliers of the generic type in structural and functional terms. This object is achieved first and foremost, in the case of such pliers having the features of Claim 1, this being based on the fact that the spring drive -comprises a spring which is supported on the two pliers legs and is formed so as to effect both expansion of the pliers legs into a spaced-apart position and displacement of the movable pliers leg into the largest opening position of the mouth, with rotation of the 2 WO 00/13856 PCT/EP99/06560 pliers leg by said spring, it being the case that a rotary support of the spring is formed on the pliers leg on at least one side and on this side, in the non-actuated state, the spring butts against a rotary stop formed on the pliers- leg, it being the case that, upon displacement of the movable pliers leg into a workpiece-gripping closed position of the mouth, the spring is released from the rotary stop only with the actuation of force when the pliers-mouth jaws are butting against the workpiece. This gives a self-contained force system integrated in a regulating element. The spring is prestressed such that, when the pliers are released, the movable pliers leg snaps into the open position. It is advantageous then for the regulating element to be formed by a spring which is supported on the two pliers legs and, at the same time, biasses the pliers mouth into the open position. The rotary stop is formed as a supporting flank. This can also easily be taken into account in terms of moulding technology. It is further proposed that the leg spring has two spring sections of different stiffnesses. This results in an operational sequence of the spring drive. The invention also proposes that the different stiffnesses are achieved by different lengths of the spring sections. It is further provided that the spring is subdivided into the two spring sections by means of a spring coil. Such a spring coil, which may be formed with a plurality of layers, contains an adapted stored spring-force reserve. It is further provided that the points of articulation of the spring are disposed at different spacings from the pliers mouth. In specific terms, this takes place such that the point of articulation of the longer spring section is closer to the pliers mouth. In addition, one configuration is implemented to the effect that the shorter spring section is supported at a location beyond which it is not possible to pass in the direction of the pliers mouth. Precautions are taken here for a capacity for -"S WO 00/13856 PCT/EP99/06560 rotary movement of the shorter spring section at the point of articulation to be limited in angular terms. It is provided hete that the angle of rotation is an acute angle. It is further provided that the spring has two coils located one beside the other. This gives an even more balanced force system, in particular a good spring characteristic. In the case of pliers having the features of the preamble of Claim 1, it is advantageous for the regulating element to be made up of a spring section and a rigid section. Like the short spring section, this rigid section is also supported at a location beyond which it is not possible to pass in the direction of the pliers mouth. In the case of this solution, it is also proposed that the spring section is formed by a helical spring. This may be a leaf spring with an end turn which encloses a central non-round cross-section in a slip-free manner. It is advantageous here for the rigid section to be a link, at one end of which the spring element is fastened in the manner described and the other end of which is disposed rotatably on the pliers leg, in this case too, in turn, with th% proviso of being supported at a location beyond which it is not possible to pass. It is advantageous in terms of stability if the link is formed in a pair and a free space for the spring and the spting fastening is left by virtue of the two links being spaced apart. It is advantageous here for the spring fastening to be achieved by a carrying pin which penetrates the group of turns of the spring coil and connects the links. The spring is thus secured reliably, it is favourable here, moreover, for the spring section of the spring in the form of a rotary leg spring, said spring section being directed towards the rigid section, to be supported on the rigid section. The support may be formed by a tongue cut out of the link; alternatively, the support may be formed by a pin which likewise connects the links. It is then WO 00/13856 PCT/EP99/06560 proposed that the spring is supported on two rigid sections which are connected to one another in the manner of a toggle lever. In order to assist the biassing force of the spring, it may further be proceeded such that a second spring which is disposed on the handle section preloads one of the rigid sections in order to produce a straightened-out position of the rigid sections in relation to one another. As regards the abovementioned straightened-out position, it may be said that, in the straightened-out state, the two rigid sections enclose between them an angle of less than 18 0° which opens on the mouth side. This prevents a dead-centre position of the rigid sections, which are connected to one another in the manner of a toggle joint, between the points of articulation of the pliers legs. A further feature is that the rigid section connected to the further spring is double-armed. The spring action thus takes place in the same direction as the other, first spring. Pliers with a minimum number of components are achieved if the spring is formed as a clip spring with clip-spring arms and a clip-spring bend, the clip-spring arms being supported on one of the pliers legs and the clip-spring bend being supported on another of the pliers legs. The spring and regulating elements are configured integrally with one another. The clip-spring arms or the clip-spring bend are/is supported by means of a rigid section mounted rotatably on a pliers leg. The spring prestressing of the spring drive and the spring force itself are applied here in that the freely projecting clip-spring arms are supported rotatably on a rigid section or a pliers leg via different axes of rotation. The spacing between the axes of rotation is converted into the desired spring force by the pliers legs being pivoted. The clip-spring arms are formed to be of different lengths. This, in conjunction with the spaced-apart axes of rotation, results in a torsional action in the clip-spring bend and also in a specific 5 WO 00/13856 PCT/EP99/06560 curvature of the clip-spring arms. The clip-spring arms may be curved, for example in the manner of an already slight precurvature. The curvature is formed to be concave in the direction facing the pliers mouth. It is also proposed that formed on the rigid section is a stop which interacts with the spring when the spring drive is in the straightened-out position. In addition, it may be advantageous for the clip-spring bend to be of helical form. This makes it possible to achieve a bearing eyelet at #the same time. The bearing eyelet is not made to undergo a torsional action. Moreover, it is provided that the clip-spring bend is supported in a longitudinally movable manner on a pliers leg. A straightforward association is achieved here in that the clip-spring bend is accommodated in a slot of a pliers leg. In order for it to be possible to maintain, by straightforward means, the sequence of the mouth being closed and applying a forceful grip, it is proposed that the support of the clip-spring bend is of profiled form with an initial supporting surface which is inclined in relation to the longitudinal direction of the pliers leg and grips below the clip-spring bend. An alternative feature consists in that a tension spring acting in the longitudinal pliers-leg direction acts on the clip-spring bend. The subject matter of the invention is explained hereinbelow with reference to exemplary embodiments illustrated in the drawing, in which: Figure 1 shows a first exemplary embodiment of the pliers in side view, in a spring-loaded, basic position, Figure 2 shows an enlargement of Figure 1, illustrating the position of the articulation bolt, Figure 3 shows the pliers in side view, in the closed state, Figure 4 shows the rear view of the pliers, WO 00/13856 PCT/EP99/06560 Figure 5 shows a side view of the pliers gripping an object, Figure 6 shows an enlargement showing the position then assumed by the articulation bolt, Figure 7 shows an enlargement of the articulation of the spring, Figure 8 shows the section along line VIII-VIII in Figure 7, Figure 9 shows the spring in side view, Figure 10 shows the spring in plan view, Figure 11 shows a second exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 12 shows the other side of the pliers in a position according to Figure 11, Figure 13 shows these pliers in the closed state, Figure 14 shows the pliers gripping an object, Figure IS shows the spring of these pliers in side view, Figure 16 shows a plan view thereof, Figure 17 shows a third exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 18 shows a fourth exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 19 shows a fifth exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 20 shows a sixth exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 21 shows, on an enlarged scale, the section along line XXI-XXI in Figure 20, Figure 22 shows a seventh exemplary embodiment of the pliers in side view, in a spring-loaded, open position, WO 00/13856 PCT/EP99/06560 Figure 22a shows a variant of the support of the spring, Figure 23 shows -the spring illustrated on its own, showing the guided articulation in the one pliers leg, Figure 24 shows an eighth exemplary embodiment of the pliers in side view, in a spring-loaded, open position, Figure 25 shows these pliers in side view, in the closed state without an object, Figure 26 shows a ninth exemplary embodiment of the pliers in side view, in a spring-loaded, open position, and Figure 27 shows these pliers in side view, in the closed state without an object. The pliers 1 of all the exemplary embodiments have two pliers legs 2 and 3 crossing over one another. In the crossover region, these pliers legs are connected in an articulated manner in relation to one another via an articulation bolt 4. A pliers mouth M is located above said crossover region of the pliers legs 2, 3. Below the crossover region, defined by the articulation bolt 4, the pliers legs 2, 3 merge into elongate handle sections 7, 8. The articulation bolt 4 penetrates a longitudinal slot 9 of the pliers leg 2. The articulation bolt 4 is mounted in the penetrated pliers leg 3. The articulation bolt 4 carries a catch 10. This interacts with tooth gaps 11 of a mouth-side tooth profiling of the penetrating pliers leg 2. Figure 2 shows the disengagement position in Figure 1, and Figure 6 shows the engagement position of this latching -^toothing formation which is assumed in Figure 5. The longitudinal slot 9 and tooth gaps 11 may be formed on the penetrated pliers leg 3 rather than on the penetrating pliers leg. In this case, the penetrated pliers leg 3 corresponds geometrically to the pliers WO 00/13856 PCT/EP99/06560 leg 2 in the attached drawing, the only difference being that this pliers leg then has two slots spaced apart transversely to the longitudinal pliers plane and provided with tooth gaps 11. The penetrating pliers leg, otherwise formed, in geometrical terms, in accordance with the pliers leg 2 according to the attached drawing, is accommodated in the vertical spacing between the slots. In order to change the size of the pliers mouth M, the corresponding insertion connection has an appropriate free space F. This is located in the penetrated pliers leg 3. A spring drive 12 keeps the pliers 1 in a basic position, in which the mouth is open (see Figures 1, 11, 17, 18, 19, 20, 22, 24, 26). For this purpose, the spring drive 12, which is accommodated in the interspace of the pliers legs 2, 3, acts so as to expand the pliers legs. The end position is defined by striking against the lower end of the longitudinal slot 9. The spring drive 12 has prestressing, depicted as a chain-dotted position in Figure 1. To this extent, the open position is biassed effectively but such that it can be overcome. With closure of the expanded pliers legs 2, 3, the pliers jaw 6 of the displaceably and pivotably mounted pliers leg 3 moves in the direction of the pliers jaw 5 of the penetrating pliers leg 2. This can be seen from Figure 3. Accordingly, the open position according to Figure 1 is obviously achieved fully automatically by the abovedescribed spring loading once the handle sections 7, 8 of the pliers legs 2, 3 have been relieved of loading. The spring drive 12, which passes through or bridges over the intervening region between the pliers legs 2, 3, performs the function of a regulating element 13 at the same time. This element, supported by the penetrating pliers leg 2, projects freely on the intervening region side. It forms a type of extension WO 00/13856 PCT/EP99/06560 arm, it being the case that, in a first movement section of the spring drive 12, the pliers-mouth jaws 5, 6 move towards one another and, in a second movement section, the catch 10 of the articulation bolt 4 engages in the latching toothing formation 11. Accordingly, forced rotation of the movable, that is to say penetrated pliers leg 3, or of the pliers-mouth jaw 6 of the same, about the articulation bolt 4 can be carried out. Coinciding movements take place here. In the first exemplary embodiments, the unit comprising spring drive/regulating element 12/13 forms a spring 14, more precisely a leg spring. The spring 14 has its ends articulated on one of the pliers legs 2, 3 in each case. The point of articulation on the penetrated pliers leg 3 is designated 15. It is a rotary point of articulation. The point of articulation realized on the penetrating pliers leg 2 is designated 16. The geometrical axes of the points of articulation 15, 16 are spatially parallel to the geometrical axis of the articulation bolt 4. The spring 14 or leg spring has two spring sections of differently effective stiffnesses. The one spring section a is more resilient. The other spring section is designated b. Its resilience may even approach zero. This spring section b is associated with the pliers leg 2. The different resiliences are based on different lengths of the spring sections a, b made of wire, irrespective of whether one of the spring sections also includes a (further) coil 17 such as, for example, the exemplary embodiment of Figure 11. The two spring sections a, b, running in a more straightened-out or curved manner, extend from a common spring coil 17. This is located on that side of the spring 14 which is directed towards the articulation bolt 4. 10 WO 00/13856 PCT/EP99/06560 The points of articulation 15, 16 of the spring are disposed at different spacings from the pliers mouth M. The point of articulation 15 of the longer spring section a is thus closer to the pliers mouth M. The closeness becomes even more pronounced when the pliers 1 are closed or an object is gripped. The corresponding object, e.g. a tube, is designated 18 {see,, for example, Figure 5) . The spring deflection of the leg spring takes place, in respect of the spring coil 17, on the handle-section side. The points of articulation 15, 16 and the end-supported position of the articulation bolt 4 form an inherently stable articulation triangle, effected by the restoring force of the prestressed spring 14. In this arrangement, in other words in the basic position, the shorter spring section b is supported on the handle-leg side. The supporting flank, as rotary stop, is designated 19. It is located such that the shorter spring section b can only pivot about its point of articulation 16 in the direction away from the articulation bolt. Also extending from the supporting surface 19 is a nose 20 which secures that end section of the shorter spring section b which is in the vicinity of the articulation. The capacity for rotary movement of the shorter spring section b, moreover, is limited in angular terms. This is a free, acute-angled movement range. The acute angle encloses approximately 30 to 40°. As can clearly be gathered from Figure 7, the shorter spring section b can also engage against a stop edge 21 in the vicinity of the border. Further pivoting of this section means resistance and thus an increased spring force of the spring 14. As can be gathered from Figures 9 and 10, the ^spring 14 forms three layers of turns in the region of the spring coil 17. These layers of turns overlap one another on the border side under loading, which aids, i.e. increases, the spring action. The one end forming WO 00/13856 PCT/EP99/06560 the longer spring section a is rolled into a bearing eyelet 22 at the end. The other end forms an angled bearing pin 23. The spring drive 12 of the second exemplary embodiment is basically of the same construction. The reference numerals are transferred analogously, without repetitions in the text. The difference is that the spring 14 forms two spring coils 17. These adjoin one another directly to form, in principle, a figure of eight. The supporting surface, which is also selected in this case in relation to the shorter spring section b, is designated 19. In this case it extends, rather than transversely, in the longitudinal direction of the penetrating pliers leg 2. However, the shorter spring section b is now very much straightened out, whereas, according to the first exemplary embodiment, it exhibits an obtuse-angled bend. This is predetermined and, when striking against the stop edge 21, can become even more pronounced, that is to say can become part of the spring action. Let us now deal with the pliers 1 according to the third exemplary embodiment. In this case, instead of an integral formation of the spring drive 12, the latter has two parts. In this case too, the reference symbols are used analogously, in some cases without repetitions in the text. In this case, the regulating element 12 comprises a spring section a and a rigid section b". In relative terms, this shorter spring section forms an element which is for all practical purposes not resilient. The spring section a is the outer end section of a helical spring 25. This has a gently arcuate, convex profile, as seen from the handle sections 7, 8, and merges into the bearing eyelet 22. The inner end turn of the helical spring 25 is fastened on the rigid section b" . It is secured on a square stub 26. This projects transversely from a link 27. The link 27 may be formed in a pair such that the wound section of the 12 WO 00/13856 PCT/EP99/06560 helical spring 25 is concealed, that is to say obtains, in a manner of speaking, a spring chamber. The square stub 26 is connected firmly to the link or links 27. The other end of the link 27 is articulated rotatably on the penetrating pliers leg 2, in this case also forming the point of articulation 16 explained. This exemplary embodiment also takes the precaution of the shorter section of the spring drive 12, thus in this case of the rigid section b", being supported at a location beyond which it is not possible to pass in the direction of the pliers mouth M, this being realized by the illustrated supporting flank 19 of the pliers leg 2. The abovedescribed pliers function as follows: by virtue of the pliers legs 2, 3 being closed, the spring drive 12 is brought, counter to the restoring force of the spring 14, into a more pronounced V-position in relation to its legs. The longer spring section a passes into a position in which it runs in virtually the same direction as the pliers leg 3. The pliers jaw 6 runs in the direction of the pliers jaw 5. If an object 18 is then gripped by these jaws, the spring 14 yields in the direction of the handle sections 7, 8. This produces a lever action to the effect that the catch 10 enters into the tooth gaps 11 of the latching toothing formation. The abovedescribed forced rotation of the movable pliers-mouth jaw 6 commences, with a powerful grip being applied in the process. The shorter spring section, be this resilient or rigid, follows this bending-in movement of the spring bridge. By virtue of the pliers being let go, the object 18 is released and the pliers 1 return into their spring-loaded, ready-to-grip open position. The spring is thus advantageously used such that it also performs the function of an actuating member (regulating element 13) . Of course - as indicated - it is also possible for the springs to be realized in the form of a leaf spring, as can also be 13 WO 00/13856 PCT/EP99/06560 seen in the fourth embodiment according to Figure 18. When the mouth M is closed in the empty state, it is essentially just the one, longer spring section a which acts resiliently, utilizing a spring-force reserve stored in the form of coils 17 (see also Figure 18) . The shorter spring section remains, for all practical purposes, in its basic position, predetermined by a supporting flank. If, in contrast, an object is gripped by the mouth M of the pliers 1, pivoting of the shorter spring section b, be this resilient or rigid, takes place in a type of reverse thrust, via the longer spring section a. Instead of, as illustrated, an essentially V-shaped profile of the spring 14, an S-shaped profile is also conceivable (see Figure 18), the cross-piece of the S having the spring coil 17. The longer spring section a is aligned as illustrated in the exemplary embodiments, whereas the shorter spring section b has a U-bend 28 in the direction of the articulation pin 4. This spring section is thus somewhat longer and also more resilient. A balanced length ratio is preferably present here, whereas the exemplary embodiments illustrated have a ratio between a:b of approximately 3:1. In all the exemplary embodiments, the coil hollows may be closed by plates or buttons which can be connected in the manner of push buttons. The fifth exemplary embodiment, illustrated in Figure 19, of the pliers 1 is similar in structural terms to the pliers according to the third exemplary embodiment, it also being the case here that the regulating element 13 comprises a combination of spring section a and rigid section b" . The rotary stop, also provided here, in the form of a supporting flank 19 ensures that the spring drive 12 swings out in the direction away from the mouth. The reference numerals are used analogously, in some cases without repetitions in the text. 14 WO 00/13856 PCT/EP99/06560 A paired arrangement of the links 27 can be gathered from Figure 19. These links extend congruently and, in outline, describe substantially a droplet form. The point of articulation 16 to the pliers leg 2 is located in the narrower zone. Spacing apart the two links 27 from one another allows for a free space in which the spring coil 17 of the spring 14, realized as a rotary leg spring, is accommodated. The group of turns of the spring coil 17 is secured in the resulting spring chamber. The corresponding spring fastening is achieved by a carrying pin 29. This passes through the pair of links 27 and, in the process, penetrates the group of turns of the spring 14. The carrying pin 29 may be dimensioned such that, with account being taken of the capacity for movement of the spring coil 17, a slip-free mount is provided. As can further be gathered from the drawing of Figure 19, the spring section b does not continue as far as the point of articulation 16; rather, it is supported within the free space of the pair of links 27. For this purpose, the spring section b engages against a pin 30, which penetrates the free space, forming the spring chamber, at a spacing from the carrying pin 29. The ends of the pins 29 and 30 are fastened in the plate-like parts of the link 27. Such a rotary leg spring is also used in the sixth exemplary embodiment. Reference will now be made to Figures 20 and 21. This spring 14 is associated with rigid sections b" which are connected to one another in the manner of a toggle joint. The toggle-joint pin here is designated 31. Those ends of the two rigid sections b" which are oriented away from one another are connected in an articulated manner to the pliers legs 2, 3 via points of articulation 15, 16. It is also the case here that the toggle joint bends out in the direction away from the mouth. WO 00/13856 PCT/EP99/06560 The two rigid sections b" are formed by U-profile sections which are nested one- inside the other. In the region of the toggle-joint pin 31, stop-forming overlapping of the ends at this location is ensured. This gives a defined straightened-out position of the two rigid sections b", this position being effected by the spring 14. Accordingly, the spring sections, both designated a in this case, subject the rigid sections b" to loading in the direction away from the mouth. The spring drive 12, which expands the pliers legs 2, 3 or the handle sections 7, 8 thereof, is also assisted here by a further spring 32 which is disposed on the handle section 8. This further spring, accordingly, acts in the same direction as the straightened-out position of the rigid sections b" in relation to one another, the latter sections thus being preloaded very well. As far as the straightened-out position is concerned, it should be explained that, in the straightened-out state, the two rigid sections enclose between them an angle of less than 180° which opens on the mouth side. The rigid sections b", which are connected to one another in the manner of toggle joints, can thus only bend out in the direction away from the mouth. The toggle-joint pin 31 cannot pass into a dead-centre position between the points of articulation 15 and 16. It is also the case that all other spring drives 12 can only bend out in the direction away from the mouth, e.g. on account of the correspondingly handle-section-side curved profile or of an angled profile of the rigid section b" and spring section a. The further spring 32 is connected to a rigid section b" " which extends beyond the point of articulation 15. This rigid section b"" gives the rigid section b" a double-armed configuration. The spring 32 is a tension spring. Conversely, it would also be possible for the shorter arm of the double-armed rigid 16 WO 00/13856 PCT/EP99/06560 section b"/b"" to act there as a compression spring. The spring 32 is expediently accommodated in the free space F of the pliers leg 3. The pliers 1 according to the seventh exemplary embodiment (see, for example, Figure 22) have, as spring 14, a clip spring B. This has two clip-spring arms 33, 33" . The clip spring B, which forms a sort of closed U, has a clip-spring bend 33"" of relatively short form. The clip-spring arms 33, 33" are of different lengths. The one which is designated 33 is the shorter clip-spring arm. The basis for dimensions is the clip-spring bend 33"", which is located transversely to the clip-spring arms. The clip spring B forms the link-like regulating element 13 as well as the spring drive 12. This regulating element is positioned obliquely in relation to a plane of symmetry of the pliers 1. In the seventh exemplary embodiment, the clip-spring bend 33"" extends in a position which is more remote from the mouth than the freely projecting ends of the two clip-spring arms 33, 33". In the exemplary embodiment mentioned, the clip-spring arms 33, 33" are supported on the pliers leg designated 3 so as to form points of articulation. The clip-spring bend 33"" is supported on the pliers leg designated 2. In this respect, there are two points of articulation on the pliers leg 3. The point of articulation for the shorter clip-spring arm 33 is designated 15" and that of the longer clip-spring arm 33" is designated 15"". The latter point of articulation is closer to the mouth. The other end of this regulating element 13 is formed as a clip-spring bend of U-shaped configuration. The clip-spring bend 33"" acts as a torsion spring. The clip-spring bend 33" " is supported on the pliers leg 2 and guided in a longitudinally movable manner. It passes through a slot 34 of the pliers leg 2 and is accommodated therein. The slot 34 is of such a length that, when the pliers 1 close, the corresponding 17 WO 00/13856 PCT/EP99/06560 yielding movement can be carried out. The corresponding yielding displacement of the regulating element 13 is not illustrated since it is easily conceivable. By virtue of the handle sections 7, 8 being advanced towards one another, the points of articulation 15", 15"" change spatially in relation to one another by the clip-spring arms 33, 33", which according to Figure 22 are still in an acute-angled expansion position, advancing towards one another. The resulting longitudinal constraint on the shorter clip-spring arm 33 stores further spring force, which is also present already from a certain prestressing. Once the handle sections 7, 8 have been let go, this overall force always results in the open position, which can be seen from Figure 22, being produced. With the pivoting of the pliers legs 2, 3, the U-clip-spring bend 33"", functioning as a displaceable point of articulation 16", is initially still supported. This can be achieved in two ways. In this respect, Figure 22 provides a tension spring 35. This, under a certain prestressing, keeps the point of articulation 16", in other words the U-clip-spring bend 33"", initially in abutment against the mouth-side end of the slot 34. Accordingly, the catch 10 engages simultaneously or immediately in the tooth gap 11. The object 18 is gripped. This is followed by the necessary displacement of the clip-spring bend 33"" as a result of the supporting action of the regulating element 13. ^ The latter yields in the slot 34 in the direction of the end of the handle section 7. In this case, the force of the tension spring 35 is overcome for all practical purposes suddenly. Another embodiment of a supporting step which /can be overcome at will is represented in Figure 22a. The procedure here is such that the U-clip-spring bend 33"" is supported via a profiling, in specific terms by an initial supporting surface 36 which is inclined in 18 WO 00/13856 PCT/EP99/06560 relation to the longitudinal direction of the pliers leg 2 and grips below the clip-spring bend 33"". In Figure 22, the tension spring 35 is accommodated in a free space 37 of the pliers leg 2, said free space corresponding approximately to the free space F. Said free space 37 also extends over the entire length of the slot 34. The fastening means for the spring 14 will not otherwise be explained in any more detail. Alternatively, it is also possible for the clip spring B to be supported merely on the inside of the pliers leg 2, guided on a rail. For this purpose, all that is required is for the clip-spring bend 33"" to have a corresponding guide profiling, for example in the form of a W-shaped fold of the wire of the clip spring B. The rail in this case could have a supporting nose 38 which defines the open position according to Figure 22. Nevertheless, the tension spring 35 would also be used in this version. The eighth exemplary embodiment is based, according to Figure 24, once again on a combination of spring section a and rigid section b" , in this case formed, again, by a link 27. The reference numerals are used analogously, where necessary for understanding, here too in some cases without repetitions in the text. However, the clip spring B described in detail in relation to the seventh exemplary embodiment is used here. In this case, however, it is the other way round, to be precise such that the clip-spring arms 33, 33" now act, or are supported on, a rigid section b" which is mounted rotatably on a pliers leg, to be precise the pliers leg designated 2. This provides, in a manner of speaking, an indirect support of the spring. It is also -the case here that the freely projecting clip-spring arms, 33, 33" are mounted on the self-rotatable rigid section b" such that they can be rotated via different axes of rotation. It may be gathered that clip-spring arms 33, 33" of different length are also provided 19 WO 00/13856 PCT/EP99/06560 here. In this case, the shorter clip-spring arm 33 is closer to the mouth M of the pliers 1. In this exemplary embodiment too, the clip-spring arms 33, 33" also pass, with actuation of the pliers 1, into a crossed position, effected by the rigid section b" pivoting about the point of articulation 16, that is to say by the link 27. The link-side axes of rotation are designated 16" and 16"" here. Inwardly angled plug-in pins 39, 39" (see Figure 23) which form mutually overlapping ends have an axis-forming function in respect of the points of rotation both in the solution according to the seventh exemplary embodiment and in that according to the eighth exemplary embodiment. According to Figure 24, the clip-spring bend 33"" has a helical profile. It is made into a bearing eyelet 40. The hollow of the latter is penetrated by a pin providing the point of articulation 15. The clip-spring arms 33, 33" may be curved, so that, with the displacement of the axes of rotation 16", 16"" taking place by rotation of the link 27, the also force-storing bending-out action of the compressed clip-spring arm proceeds in the correspondingly predetermined direction. In the case of intrinsic prestressing of a clip-spring arm, the straightening-out pull likewise has a spring-force-producing action thereon. A movement counter to the pliers-supported three-point arrangement of the points of articulation .reacts as a restoring action, this being accompanied, moreover, by a biassing which keeps the rigid section b" in the basic position on the rotary stop of the pliers leg 2, that is to say on the supporting surface 19. The curvature is concave in the direction facing the pliers mouth M at least on one clip-spring arm. It can be gathered in relation to Figure 24 that here too, as in all the other exemplary embodiments, the bending-out movement in the direction away from the mouth takes place. Figure 25 shows the WO 00/13856 PCT/EP99/06560 mouth closed without having accommodated an object therein. It is clear that, with the mouth M filled, the pliers leg designated 3 is displaced further downwards in relation to the mouth, so that the rigid section b" is displaced into the alignment illustrated by chain-dotted lines in Figure 25. The line is designated 41. The ninth exemplary embodiment corresponds essentially to the eighth exemplary embodiment, but is based, once again, on a toggle-lever-like solution. The manner of articulation of the clip spring B has been taken over from the seventh exemplary embodiment, that is to say the formation of the points of articulation 15", 15"" on the pliers leg 3. The procedure here is such that a stop 42 which interacts with the spring 14, that is to say the clip spring B, is formed on the rigid section b". This stop is seated on the link 27 as a pin which projects beyond the outside of said link, and engages against that side of the clip spring B which is directed away from the mouth M. The clip-spring bend 33"" in this case forms the toggle-joint pin 31. With an object 18 being gripped, the toggle-joint-like unit comprising spring drive/regulating element 12/13 bends out in the direction away from the mouth, this unit, here too, having a straightened-out basic position which only allows the bending-out movement to take place in this direction. All disclosed features are pertinent to the invention. The disclosure v contents of the associated/attached priority documents (copy of the prior application) are hereby also included in full in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application. 21 We claim: 1. One-handedly actuatable, self-closing pliers (1) having two pliers legs (2,3) which are interconnected in a crossing region by means of a articulation bolt (4), a pliers mouth (M) being formed on one side of the crossing region of the pliers legs (2, 3) and handle sections (7, 8) being formed on the pliers legs (2, 3) on the opposite side below the crossing region, one pliers leg (3) which can be adjusted in the crossing region relative to the other pliers leg (2) in order to vary the size of the pliers mouth (M) having a free space (F) which is penetrated by the other pliers leg(2) or the non-adjustable pliers leg being penetrated by the adjustable pliers leg and furthermore the pliers legs (2, 3) being connected via a regulating element (13) and a spring drive (12) which biases the pliers mouth (M) into an open position, which open position is produced automatically under spring loading after unloading of the handle sections (7, 8) wherein, in addition, the pliers mouth jaws (5, 6) move towards one another in first movement section of the spring drive (12) and a catch (10) of the articulationbolt (4) engages in a latching tooth formation (11) in a second movement section, whereafter a forced rotation of the movable pliers mouth jaw (6) about the articulation pin (4) can be carried out, characterized in that the spring drive (12) simultaneously fulfils the function of the regulating element (13), this spring drive (12) being composed of a spring (14) with two spring sections (a, bl) one spring section (bl) being formed as a rigid section the rigid section being connected to the other pliers limb (2), and the spring section (a) being connected to the adjustable leg (3), a rotation support (19) for the rigid section being provided on the other pliers leg (2) such that in the unactuated state the rigid section engages against the rotation support (19) provided on the other pliers leg (2), and in that, upon displacement of the adjustable pliers leg (3) into a mouth closing position gripping a workpiece, the rigid section comes clear of the rotation support (19) only after forced actuation with the pliers mouth jaws (5, 6) engaging against the workpiece. 22 2. Pliers as claimed in claim 1, wherein the rigid section (bl) is a link (27) at one end of which the spring element is sourced, and whose other end is rotatably disposed on the pliers limb (2). 3. Pliers as claimed in claim 1, wherein the link (27) is of paired construction and leaves a free space for the spring (14) and the spring fastening by spacing the two links (27). 4. Pliers as claimed in one of claims 1 to 3, wherein the spring section (a) is formed by a helical spring (25). 5. Pliers as claimed in claim 3 or 4, wherein the spring fastening is achieved by a carrying pin (29) which penetrates the turn packet of the spring coil (17)-and connects the links (27). 6. Pliers as claimed in one of claims 2 to 5, wherein the spring section (b) facing the rigid section (bl) of the spring (14) formed as a rotary leg spring is supported on the rigid section (b I). 7. Pliers as claimed in claim 6, wherein the support is formed by a pin (30) likewise connecting the links (27). S. Pliers as claimed in any one of claims 1 to 7, wherein the spring (14) is formed as a clip spring (B) with clip spring arms (33, 331) and a bend of the clip spring (3311), the clip spring arms (33, 331) or the bend of the clip spring (3311) being rotatably supported on one pliers leg (2) by means of the positioned rigid section (bl). 9. Pliers as claimed in claim 8, wherein the clip spring arms (33, 331) are rotatably supported on a rigid section (bl) or a pliers leg (2 or 3) via different axis fo rotation (151, 1511, 161, 1611). 23 10. Pliers as claimed in either of claims 8 and 9, wherein the clip spring arms (33, 331) are formed to be of different lengths. 11. Pliers as claimed in one of claims 8 to 10, wherein the clip spring arms (33, 331) have a curved profile. 12. Pliers as claimed in claim 11, wherein the curve is concave facing the pliers mouth (M). 13. Pliers as claimed in one of claims 8 to 12, wherein the bend of the clip spring (3311) is U-shaped. 14. Pliers as claimed in one of claims 8 to 12, wherein the bend of the clip spring (3311) is helical. 15. Pliers as claimed in one of claims 1 to 14, wherein a stop (42) cooperating with the spring (14) in the expanded position of the spring drive (12) is provided on the rigid section (bl). Dated this the 2nd day of March, 2001. ■P H

Full Text

FORM 2
THE PATENTS ACT 1970
[39 of 1970]
&
THE PATENTS RULES 2003
COMPLETE
SPECIFICATION
[Section 10; rule 13]
"ONE-HAND ACTUATED, SELF-CLOSING PLIERS"
KNIPEX-WERK C. GUSTAV PUTSCH, of Oberkamper Strasse 13, D-42349 Wuppertal, Germany,
The following specification particularly describes and ascertains the nature of the invention, and the manner in which it is to be performed:-

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Self-closing pliers which can be actuated by one hand
The invention relates to a self-closing pliers which can be actuated by one hand, having two pliers legs which are connected to one another by means of an articulation bolt, it being the case that a pliers mouth is formed above the crossover region of the pliers legs and handle sections are formed on the pliers legs below the crossover region, it being the
case that one of the pliers legs, which can be adjusted relative to the other pliers leg in the crossover region in order to change the size of the pliers mouth, has a free space which is penetrated by the other pliers leg, or the non-adjustable pliers leg is penetrated by the adjustable pliers leg, and it being the case that, furthermore, the pliers legs are connected via a regulating element and a spring drive, which biasses the pliers mouth into an open position, which open position is produced automatically under ing loading once the handle sections have been relieved of loading, it being the case that, moreover, in a first movement section of the spring drive, the pliers-mouth jaws move towards one another and, in a second movement section, a catch of the articulation bolt engages in a latching toothing formation, whereupon forced rotation of the movable pliers-mouth jaw about the articulation bolt can be carried out.
It is an object of the invention to improve pliers of the generic type in structural and functional
terms.
This object is achieved first and foremost, in
the case of such pliers having the features of Claim 1,
this being based on the fact that the spring drive
-comprises a spring which is supported on the two pliers
legs and is formed so as to effect both expansion of the pliers legs into a spaced-apart position and displacement of the movable pliers leg into the largest opening position of the mouth, with rotation of the
2

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pliers leg by said spring, it being the case that a rotary support of the spring is formed on the pliers leg on at least one side and on this side, in the non-actuated state, the spring butts against a rotary stop
formed on the pliers- leg, it being the case that, upon displacement of the movable pliers leg into a workpiece-gripping closed position of the mouth, the spring is released from the rotary stop only with the actuation of force when the pliers-mouth jaws are
butting against the workpiece. This gives a self-contained force system integrated in a regulating element. The spring is prestressed such that, when the pliers are released, the movable pliers leg snaps into the open position. It is advantageous then for the
regulating element to be formed by a spring which is supported on the two pliers legs and, at the same time, biasses the pliers mouth into the open position. The rotary stop is formed as a supporting flank. This can also easily be taken into account in terms of moulding
technology. It is further proposed that the leg spring has two spring sections of different stiffnesses. This results in an operational sequence of the spring drive. The invention also proposes that the different stiffnesses are achieved by different lengths of the
spring sections. It is further provided that the spring is subdivided into the two spring sections by means of a spring coil. Such a spring coil, which may be formed with a plurality of layers, contains an adapted stored spring-force reserve. It is further provided that the
points of articulation of the spring are disposed at different spacings from the pliers mouth. In specific terms, this takes place such that the point of articulation of the longer spring section is closer to the pliers mouth. In addition, one configuration is
implemented to the effect that the shorter spring section is supported at a location beyond which it is not possible to pass in the direction of the pliers mouth. Precautions are taken here for a capacity for
-"S

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rotary movement of the shorter spring section at the point of articulation to be limited in angular terms. It is provided hete that the angle of rotation is an acute angle. It is further provided that the spring has two coils located one beside the other. This gives an even more balanced force system, in particular a good spring characteristic.
In the case of pliers having the features of the preamble of Claim 1, it is advantageous for the regulating element to be made up of a spring section and a rigid section. Like the short spring section, this rigid section is also supported at a location beyond which it is not possible to pass in the direction of the pliers mouth. In the case of this solution, it is also proposed that the spring section is formed by a helical spring. This may be a leaf spring with an end turn which encloses a central non-round cross-section in a slip-free manner. It is advantageous here for the rigid section to be a link, at one end of which the spring element is fastened in the manner described and the other end of which is disposed rotatably on the pliers leg, in this case too, in turn, with th% proviso of being supported at a location beyond which it is not possible to pass.
It is advantageous in terms of stability if the link is formed in a pair and a free space for the spring and the spting fastening is left by virtue of the two links being spaced apart. It is advantageous here for the spring fastening to be achieved by a carrying pin which penetrates the group of turns of the spring coil and connects the links. The spring is thus secured reliably, it is favourable here, moreover, for the spring section of the spring in the form of a rotary leg spring, said spring section being directed towards the rigid section, to be supported on the rigid section. The support may be formed by a tongue cut out of the link; alternatively, the support may be formed by a pin which likewise connects the links. It is then

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proposed that the spring is supported on two rigid sections which are connected to one another in the manner of a toggle lever. In order to assist the biassing force of the spring, it may further be proceeded such that a second spring which is disposed on the handle section preloads one of the rigid sections in order to produce a straightened-out position of the rigid sections in relation to one another. As regards the abovementioned straightened-out position, it may be said that, in the straightened-out state, the two rigid sections enclose between them an angle of less than 18 0° which opens on the mouth side. This prevents a dead-centre position of the rigid sections, which are connected to one another in the manner of a toggle joint, between the points of articulation of the pliers legs. A further feature is that the rigid section connected to the further spring is double-armed. The spring action thus takes place in the same direction as the other, first spring.
Pliers with a minimum number of components are achieved if the spring is formed as a clip spring with clip-spring arms and a clip-spring bend, the clip-spring arms being supported on one of the pliers legs and the clip-spring bend being supported on another of the pliers legs. The spring and regulating elements are configured integrally with one another. The clip-spring arms or the clip-spring bend are/is supported by means of a rigid section mounted rotatably on a pliers leg. The spring prestressing of the spring drive and the spring force itself are applied here in that the freely projecting clip-spring arms are supported rotatably on a rigid section or a pliers leg via different axes of rotation. The spacing between the axes of rotation is converted into the desired spring force by the pliers legs being pivoted. The clip-spring arms are formed to be of different lengths. This, in conjunction with the spaced-apart axes of rotation, results in a torsional action in the clip-spring bend and also in a specific
5

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curvature of the clip-spring arms. The clip-spring arms may be curved, for example in the manner of an already slight precurvature. The curvature is formed to be concave in the direction facing the pliers mouth. It is also proposed that formed on the rigid section is a stop which interacts with the spring when the spring drive is in the straightened-out position. In addition, it may be advantageous for the clip-spring bend to be of helical form. This makes it possible to achieve a bearing eyelet at #the same time. The bearing eyelet is not made to undergo a torsional action. Moreover, it is provided that the clip-spring bend is supported in a longitudinally movable manner on a pliers leg. A straightforward association is achieved here in that the clip-spring bend is accommodated in a slot of a pliers leg. In order for it to be possible to maintain, by straightforward means, the sequence of the mouth being closed and applying a forceful grip, it is proposed that the support of the clip-spring bend is of profiled form with an initial supporting surface which is inclined in relation to the longitudinal direction of the pliers leg and grips below the clip-spring bend. An alternative feature consists in that a tension spring acting in the longitudinal pliers-leg direction acts on the clip-spring bend.
The subject matter of the invention is explained hereinbelow with reference to exemplary embodiments illustrated in the drawing, in which: Figure 1 shows a first exemplary embodiment of the
pliers in side view, in a spring-loaded,
basic position, Figure 2 shows an enlargement of Figure 1,
illustrating the position of the articulation
bolt, Figure 3 shows the pliers in side view, in the closed
state, Figure 4 shows the rear view of the pliers,

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Figure 5 shows a side view of the pliers gripping an
object, Figure 6 shows an enlargement showing the position
then assumed by the articulation bolt, Figure 7 shows an enlargement of the articulation of
the spring, Figure 8 shows the section along line VIII-VIII in
Figure 7, Figure 9 shows the spring in side view, Figure 10 shows the spring in plan view, Figure 11 shows a second exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 12 shows the other side of the pliers in a
position according to Figure 11, Figure 13 shows these pliers in the closed state, Figure 14 shows the pliers gripping an object, Figure IS shows the spring of these pliers in side
view, Figure 16 shows a plan view thereof, Figure 17 shows a third exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 18 shows a fourth exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 19 shows a fifth exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 20 shows a sixth exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 21 shows, on an enlarged scale, the section
along line XXI-XXI in Figure 20, Figure 22 shows a seventh exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position,

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Figure 22a shows a variant of the support of the
spring, Figure 23 shows -the spring illustrated on its own,
showing the guided articulation in the one
pliers leg, Figure 24 shows an eighth exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, Figure 25 shows these pliers in side view, in the
closed state without an object, Figure 26 shows a ninth exemplary embodiment of the
pliers in side view, in a spring-loaded, open
position, and Figure 27 shows these pliers in side view, in the
closed state without an object. The pliers 1 of all the exemplary embodiments have two pliers legs 2 and 3 crossing over one another. In the crossover region, these pliers legs are connected in an articulated manner in relation to one another via an articulation bolt 4.
A pliers mouth M is located above said crossover region of the pliers legs 2, 3. Below the crossover region, defined by the articulation bolt 4, the pliers legs 2, 3 merge into elongate handle sections 7, 8.
The articulation bolt 4 penetrates a longitudinal slot 9 of the pliers leg 2. The articulation bolt 4 is mounted in the penetrated pliers leg 3. The articulation bolt 4 carries a catch 10. This interacts with tooth gaps 11 of a mouth-side tooth profiling of the penetrating pliers leg 2. Figure 2 shows the disengagement position in Figure 1, and Figure 6 shows the engagement position of this latching -^toothing formation which is assumed in Figure 5. The longitudinal slot 9 and tooth gaps 11 may be formed on the penetrated pliers leg 3 rather than on the penetrating pliers leg. In this case, the penetrated pliers leg 3 corresponds geometrically to the pliers

WO 00/13856 PCT/EP99/06560
leg 2 in the attached drawing, the only difference being that this pliers leg then has two slots spaced apart transversely to the longitudinal pliers plane and provided with tooth gaps 11. The penetrating pliers leg, otherwise formed, in geometrical terms, in accordance with the pliers leg 2 according to the attached drawing, is accommodated in the vertical spacing between the slots.
In order to change the size of the pliers mouth M, the corresponding insertion connection has an appropriate free space F. This is located in the penetrated pliers leg 3.
A spring drive 12 keeps the pliers 1 in a basic position, in which the mouth is open (see Figures 1, 11, 17, 18, 19, 20, 22, 24, 26). For this purpose, the spring drive 12, which is accommodated in the interspace of the pliers legs 2, 3, acts so as to expand the pliers legs. The end position is defined by striking against the lower end of the longitudinal slot 9.
The spring drive 12 has prestressing, depicted as a chain-dotted position in Figure 1. To this extent, the open position is biassed effectively but such that it can be overcome. With closure of the expanded pliers legs 2, 3, the pliers jaw 6 of the displaceably and pivotably mounted pliers leg 3 moves in the direction of the pliers jaw 5 of the penetrating pliers leg 2. This can be seen from Figure 3. Accordingly, the open position according to Figure 1 is obviously achieved fully automatically by the abovedescribed spring loading once the handle sections 7, 8 of the pliers legs 2, 3 have been relieved of loading.
The spring drive 12, which passes through or bridges over the intervening region between the pliers legs 2, 3, performs the function of a regulating element 13 at the same time. This element, supported by the penetrating pliers leg 2, projects freely on the intervening region side. It forms a type of extension

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arm, it being the case that, in a first movement section of the spring drive 12, the pliers-mouth jaws 5, 6 move towards one another and, in a second movement section, the catch 10 of the articulation bolt 4 engages in the latching toothing formation 11. Accordingly, forced rotation of the movable, that is to say penetrated pliers leg 3, or of the pliers-mouth jaw 6 of the same, about the articulation bolt 4 can be carried out. Coinciding movements take place here.
In the first exemplary embodiments, the unit comprising spring drive/regulating element 12/13 forms a spring 14, more precisely a leg spring.
The spring 14 has its ends articulated on one of the pliers legs 2, 3 in each case. The point of articulation on the penetrated pliers leg 3 is designated 15. It is a rotary point of articulation. The point of articulation realized on the penetrating pliers leg 2 is designated 16. The geometrical axes of the points of articulation 15, 16 are spatially parallel to the geometrical axis of the articulation bolt 4.
The spring 14 or leg spring has two spring sections of differently effective stiffnesses. The one spring section a is more resilient. The other spring section is designated b. Its resilience may even approach zero. This spring section b is associated with the pliers leg 2.
The different resiliences are based on different lengths of the spring sections a, b made of wire, irrespective of whether one of the spring sections also includes a (further) coil 17 such as, for example, the exemplary embodiment of Figure 11.
The two spring sections a, b, running in a more straightened-out or curved manner, extend from a common spring coil 17. This is located on that side of the spring 14 which is directed towards the articulation bolt 4.
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The points of articulation 15, 16 of the spring are disposed at different spacings from the pliers mouth M. The point of articulation 15 of the longer spring section a is thus closer to the pliers mouth M. The closeness becomes even more pronounced when the pliers 1 are closed or an object is gripped. The corresponding object, e.g. a tube, is designated 18 {see,, for example, Figure 5) . The spring deflection of the leg spring takes place, in respect of the spring coil 17, on the handle-section side.
The points of articulation 15, 16 and the end-supported position of the articulation bolt 4 form an inherently stable articulation triangle, effected by the restoring force of the prestressed spring 14. In this arrangement, in other words in the basic position, the shorter spring section b is supported on the handle-leg side. The supporting flank, as rotary stop, is designated 19. It is located such that the shorter spring section b can only pivot about its point of articulation 16 in the direction away from the articulation bolt. Also extending from the supporting surface 19 is a nose 20 which secures that end section of the shorter spring section b which is in the vicinity of the articulation. The capacity for rotary movement of the shorter spring section b, moreover, is limited in angular terms. This is a free, acute-angled movement range. The acute angle encloses approximately 30 to 40°.
As can clearly be gathered from Figure 7, the shorter spring section b can also engage against a stop edge 21 in the vicinity of the border. Further pivoting of this section means resistance and thus an increased spring force of the spring 14.
As can be gathered from Figures 9 and 10, the
^spring 14 forms three layers of turns in the region of
the spring coil 17. These layers of turns overlap one
another on the border side under loading, which aids,
i.e. increases, the spring action. The one end forming

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the longer spring section a is rolled into a bearing eyelet 22 at the end. The other end forms an angled bearing pin 23.
The spring drive 12 of the second exemplary embodiment is basically of the same construction. The reference numerals are transferred analogously, without repetitions in the text. The difference is that the spring 14 forms two spring coils 17. These adjoin one another directly to form, in principle, a figure of eight. The supporting surface, which is also selected in this case in relation to the shorter spring section b, is designated 19. In this case it extends, rather than transversely, in the longitudinal direction of the penetrating pliers leg 2. However, the shorter spring section b is now very much straightened out, whereas, according to the first exemplary embodiment, it exhibits an obtuse-angled bend. This is predetermined and, when striking against the stop edge 21, can become even more pronounced, that is to say can become part of the spring action.
Let us now deal with the pliers 1 according to the third exemplary embodiment. In this case, instead of an integral formation of the spring drive 12, the latter has two parts. In this case too, the reference symbols are used analogously, in some cases without repetitions in the text. In this case, the regulating element 12 comprises a spring section a and a rigid section b". In relative terms, this shorter spring section forms an element which is for all practical purposes not resilient.
The spring section a is the outer end section of a helical spring 25. This has a gently arcuate, convex profile, as seen from the handle sections 7, 8, and merges into the bearing eyelet 22. The inner end turn of the helical spring 25 is fastened on the rigid section b" . It is secured on a square stub 26. This projects transversely from a link 27. The link 27 may be formed in a pair such that the wound section of the
12

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helical spring 25 is concealed, that is to say obtains, in a manner of speaking, a spring chamber.
The square stub 26 is connected firmly to the link or links 27. The other end of the link 27 is articulated rotatably on the penetrating pliers leg 2, in this case also forming the point of articulation 16 explained. This exemplary embodiment also takes the precaution of the shorter section of the spring drive 12, thus in this case of the rigid section b", being supported at a location beyond which it is not possible to pass in the direction of the pliers mouth M, this being realized by the illustrated supporting flank 19 of the pliers leg 2.
The abovedescribed pliers function as follows: by virtue of the pliers legs 2, 3 being closed, the spring drive 12 is brought, counter to the restoring force of the spring 14, into a more pronounced V-position in relation to its legs. The longer spring section a passes into a position in which it runs in virtually the same direction as the pliers leg 3. The pliers jaw 6 runs in the direction of the pliers jaw 5. If an object 18 is then gripped by these jaws, the spring 14 yields in the direction of the handle sections 7, 8. This produces a lever action to the effect that the catch 10 enters into the tooth gaps 11 of the latching toothing formation. The abovedescribed forced rotation of the movable pliers-mouth jaw 6 commences, with a powerful grip being applied in the process. The shorter spring section, be this resilient or rigid, follows this bending-in movement of the spring bridge. By virtue of the pliers being let go, the object 18 is released and the pliers 1 return into their spring-loaded, ready-to-grip open position.
The spring is thus advantageously used such that it also performs the function of an actuating member (regulating element 13) . Of course - as indicated - it is also possible for the springs to be realized in the form of a leaf spring, as can also be
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seen in the fourth embodiment according to Figure 18. When the mouth M is closed in the empty state, it is essentially just the one, longer spring section a which acts resiliently, utilizing a spring-force reserve stored in the form of coils 17 (see also Figure 18) . The shorter spring section remains, for all practical purposes, in its basic position, predetermined by a supporting flank. If, in contrast, an object is gripped by the mouth M of the pliers 1, pivoting of the shorter spring section b, be this resilient or rigid, takes place in a type of reverse thrust, via the longer spring section a.
Instead of, as illustrated, an essentially V-shaped profile of the spring 14, an S-shaped profile is also conceivable (see Figure 18), the cross-piece of the S having the spring coil 17. The longer spring section a is aligned as illustrated in the exemplary embodiments, whereas the shorter spring section b has a U-bend 28 in the direction of the articulation pin 4. This spring section is thus somewhat longer and also more resilient. A balanced length ratio is preferably present here, whereas the exemplary embodiments illustrated have a ratio between a:b of approximately 3:1. In all the exemplary embodiments, the coil hollows may be closed by plates or buttons which can be connected in the manner of push buttons.
The fifth exemplary embodiment, illustrated in Figure 19, of the pliers 1 is similar in structural terms to the pliers according to the third exemplary embodiment, it also being the case here that the regulating element 13 comprises a combination of spring section a and rigid section b" . The rotary stop, also provided here, in the form of a supporting flank 19 ensures that the spring drive 12 swings out in the direction away from the mouth. The reference numerals are used analogously, in some cases without repetitions in the text.
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A paired arrangement of the links 27 can be gathered from Figure 19. These links extend congruently and, in outline, describe substantially a droplet form. The point of articulation 16 to the pliers leg 2 is located in the narrower zone.
Spacing apart the two links 27 from one another allows for a free space in which the spring coil 17 of the spring 14, realized as a rotary leg spring, is accommodated. The group of turns of the spring coil 17 is secured in the resulting spring chamber. The corresponding spring fastening is achieved by a carrying pin 29. This passes through the pair of links 27 and, in the process, penetrates the group of turns of the spring 14. The carrying pin 29 may be dimensioned such that, with account being taken of the capacity for movement of the spring coil 17, a slip-free mount is provided.
As can further be gathered from the drawing of Figure 19, the spring section b does not continue as far as the point of articulation 16; rather, it is supported within the free space of the pair of links 27. For this purpose, the spring section b engages against a pin 30, which penetrates the free space, forming the spring chamber, at a spacing from the carrying pin 29. The ends of the pins 29 and 30 are fastened in the plate-like parts of the link 27.
Such a rotary leg spring is also used in the sixth exemplary embodiment. Reference will now be made to Figures 20 and 21. This spring 14 is associated with rigid sections b" which are connected to one another in the manner of a toggle joint. The toggle-joint pin here is designated 31. Those ends of the two rigid sections b" which are oriented away from one another are connected in an articulated manner to the pliers legs 2, 3 via points of articulation 15, 16. It is also the case here that the toggle joint bends out in the direction away from the mouth.

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The two rigid sections b" are formed by U-profile sections which are nested one- inside the other. In the region of the toggle-joint pin 31, stop-forming overlapping of the ends at this location is ensured. This gives a defined straightened-out position of the two rigid sections b", this position being effected by the spring 14. Accordingly, the spring sections, both designated a in this case, subject the rigid sections b" to loading in the direction away from the mouth.
The spring drive 12, which expands the pliers legs 2, 3 or the handle sections 7, 8 thereof, is also assisted here by a further spring 32 which is disposed on the handle section 8. This further spring, accordingly, acts in the same direction as the straightened-out position of the rigid sections b" in relation to one another, the latter sections thus being preloaded very well. As far as the straightened-out position is concerned, it should be explained that, in the straightened-out state, the two rigid sections enclose between them an angle of less than 180° which opens on the mouth side. The rigid sections b", which are connected to one another in the manner of toggle joints, can thus only bend out in the direction away from the mouth. The toggle-joint pin 31 cannot pass into a dead-centre position between the points of articulation 15 and 16. It is also the case that all other spring drives 12 can only bend out in the direction away from the mouth, e.g. on account of the correspondingly handle-section-side curved profile or of an angled profile of the rigid section b" and spring section a.
The further spring 32 is connected to a rigid section b" " which extends beyond the point of articulation 15. This rigid section b"" gives the rigid section b" a double-armed configuration. The spring 32 is a tension spring. Conversely, it would also be possible for the shorter arm of the double-armed rigid
16

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section b"/b"" to act there as a compression spring. The spring 32 is expediently accommodated in the free space F of the pliers leg 3.
The pliers 1 according to the seventh exemplary embodiment (see, for example, Figure 22) have, as spring 14, a clip spring B. This has two clip-spring arms 33, 33" . The clip spring B, which forms a sort of closed U, has a clip-spring bend 33"" of relatively short form. The clip-spring arms 33, 33" are of different lengths. The one which is designated 33 is the shorter clip-spring arm. The basis for dimensions is the clip-spring bend 33"", which is located transversely to the clip-spring arms.
The clip spring B forms the link-like regulating element 13 as well as the spring drive 12. This regulating element is positioned obliquely in relation to a plane of symmetry of the pliers 1. In the seventh exemplary embodiment, the clip-spring bend 33"" extends in a position which is more remote from the mouth than the freely projecting ends of the two clip-spring arms 33, 33". In the exemplary embodiment mentioned, the clip-spring arms 33, 33" are supported on the pliers leg designated 3 so as to form points of articulation. The clip-spring bend 33"" is supported on the pliers leg designated 2. In this respect, there are two points of articulation on the pliers leg 3. The point of articulation for the shorter clip-spring arm 33 is designated 15" and that of the longer clip-spring arm 33" is designated 15"". The latter point of articulation is closer to the mouth.
The other end of this regulating element 13 is formed as a clip-spring bend of U-shaped configuration. The clip-spring bend 33"" acts as a torsion spring.
The clip-spring bend 33" " is supported on the pliers leg 2 and guided in a longitudinally movable manner. It passes through a slot 34 of the pliers leg 2 and is accommodated therein. The slot 34 is of such a length that, when the pliers 1 close, the corresponding
17

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yielding movement can be carried out. The corresponding yielding displacement of the regulating element 13 is not illustrated since it is easily conceivable.
By virtue of the handle sections 7, 8 being advanced towards one another, the points of articulation 15", 15"" change spatially in relation to one another by the clip-spring arms 33, 33", which according to Figure 22 are still in an acute-angled expansion position, advancing towards one another. The resulting longitudinal constraint on the shorter clip-spring arm 33 stores further spring force, which is also present already from a certain prestressing. Once the handle sections 7, 8 have been let go, this overall force always results in the open position, which can be seen from Figure 22, being produced. With the pivoting of the pliers legs 2, 3, the U-clip-spring bend 33"", functioning as a displaceable point of articulation 16", is initially still supported.
This can be achieved in two ways. In this respect, Figure 22 provides a tension spring 35. This, under a certain prestressing, keeps the point of articulation 16", in other words the U-clip-spring bend 33"", initially in abutment against the mouth-side end of the slot 34. Accordingly, the catch 10 engages simultaneously or immediately in the tooth gap 11. The object 18 is gripped. This is followed by the necessary displacement of the clip-spring bend 33"" as a result of the supporting action of the regulating element 13. ^ The latter yields in the slot 34 in the direction of the end of the handle section 7. In this case, the force of the tension spring 35 is overcome for all practical purposes suddenly.
Another embodiment of a supporting step which
/can be overcome at will is represented in Figure 22a.
The procedure here is such that the U-clip-spring bend
33"" is supported via a profiling, in specific terms by
an initial supporting surface 36 which is inclined in
18

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relation to the longitudinal direction of the pliers leg 2 and grips below the clip-spring bend 33"".
In Figure 22, the tension spring 35 is accommodated in a free space 37 of the pliers leg 2, said free space corresponding approximately to the free space F. Said free space 37 also extends over the entire length of the slot 34. The fastening means for the spring 14 will not otherwise be explained in any more detail.
Alternatively, it is also possible for the clip spring B to be supported merely on the inside of the pliers leg 2, guided on a rail. For this purpose, all that is required is for the clip-spring bend 33"" to have a corresponding guide profiling, for example in the form of a W-shaped fold of the wire of the clip spring B. The rail in this case could have a supporting nose 38 which defines the open position according to Figure 22. Nevertheless, the tension spring 35 would also be used in this version.
The eighth exemplary embodiment is based, according to Figure 24, once again on a combination of spring section a and rigid section b" , in this case formed, again, by a link 27. The reference numerals are used analogously, where necessary for understanding, here too in some cases without repetitions in the text.
However, the clip spring B described in detail in relation to the seventh exemplary embodiment is used here. In this case, however, it is the other way round, to be precise such that the clip-spring arms 33, 33" now act, or are supported on, a rigid section b" which is mounted rotatably on a pliers leg, to be precise the pliers leg designated 2. This provides, in a manner of speaking, an indirect support of the spring. It is also -the case here that the freely projecting clip-spring arms, 33, 33" are mounted on the self-rotatable rigid section b" such that they can be rotated via different axes of rotation. It may be gathered that clip-spring arms 33, 33" of different length are also provided
19

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here. In this case, the shorter clip-spring arm 33 is closer to the mouth M of the pliers 1. In this exemplary embodiment too, the clip-spring arms 33, 33" also pass, with actuation of the pliers 1, into a crossed position, effected by the rigid section b" pivoting about the point of articulation 16, that is to say by the link 27. The link-side axes of rotation are designated 16" and 16"" here.
Inwardly angled plug-in pins 39, 39" (see Figure 23) which form mutually overlapping ends have an axis-forming function in respect of the points of rotation both in the solution according to the seventh exemplary embodiment and in that according to the eighth exemplary embodiment.
According to Figure 24, the clip-spring bend 33"" has a helical profile. It is made into a bearing eyelet 40. The hollow of the latter is penetrated by a pin providing the point of articulation 15.
The clip-spring arms 33, 33" may be curved, so that, with the displacement of the axes of rotation 16", 16"" taking place by rotation of the link 27, the also force-storing bending-out action of the compressed clip-spring arm proceeds in the correspondingly predetermined direction. In the case of intrinsic prestressing of a clip-spring arm, the straightening-out pull likewise has a spring-force-producing action thereon. A movement counter to the pliers-supported three-point arrangement of the points of articulation .reacts as a restoring action, this being accompanied, moreover, by a biassing which keeps the rigid section b" in the basic position on the rotary stop of the pliers leg 2, that is to say on the supporting surface 19. The curvature is concave in the direction facing the pliers mouth M at least on one clip-spring arm.
It can be gathered in relation to Figure 24 that here too, as in all the other exemplary embodiments, the bending-out movement in the direction away from the mouth takes place. Figure 25 shows the

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mouth closed without having accommodated an object therein. It is clear that, with the mouth M filled, the pliers leg designated 3 is displaced further downwards in relation to the mouth, so that the rigid section b" is displaced into the alignment illustrated by chain-dotted lines in Figure 25. The line is designated 41.
The ninth exemplary embodiment corresponds essentially to the eighth exemplary embodiment, but is based, once again, on a toggle-lever-like solution. The manner of articulation of the clip spring B has been taken over from the seventh exemplary embodiment, that is to say the formation of the points of articulation 15", 15"" on the pliers leg 3. The procedure here is such that a stop 42 which interacts with the spring 14, that is to say the clip spring B, is formed on the rigid section b". This stop is seated on the link 27 as a pin which projects beyond the outside of said link, and engages against that side of the clip spring B which is directed away from the mouth M. The clip-spring bend 33"" in this case forms the toggle-joint pin 31. With an object 18 being gripped, the toggle-joint-like unit comprising spring drive/regulating element 12/13 bends out in the direction away from the mouth, this unit, here too, having a straightened-out basic position which only allows the bending-out movement to take place in this direction.
All disclosed features are pertinent to the invention. The disclosure v contents of the associated/attached priority documents (copy of the prior application) are hereby also included in full in the disclosure of the application, also for the purpose of incorporating features of these documents in claims of the present application.
21

We claim:
1. One-handedly actuatable, self-closing pliers (1) having two pliers legs (2,3) which are interconnected in a crossing region by means of a articulation bolt (4), a pliers mouth (M) being formed on one side of the crossing region of the pliers legs (2, 3) and handle sections (7, 8) being formed on the pliers legs (2, 3) on the opposite side below the crossing region, one pliers leg (3) which can be adjusted in the crossing region relative to the other pliers leg (2) in order to vary the size of the pliers mouth (M) having a free space (F) which is penetrated by the other pliers leg(2) or the non-adjustable pliers leg being penetrated by the adjustable pliers leg and furthermore the pliers legs (2, 3) being connected via a regulating element (13) and a spring drive (12) which biases the pliers mouth (M) into an open position, which open position is produced automatically under spring loading after unloading of the handle sections (7, 8) wherein, in addition, the pliers mouth jaws (5, 6) move towards one another in first movement section of the spring drive (12) and a catch (10) of the articulationbolt (4) engages in a latching tooth formation (11) in a second movement section, whereafter a forced rotation of the movable pliers mouth jaw (6) about the articulation pin (4) can be carried out, characterized in that the spring drive (12) simultaneously fulfils the function of the regulating element (13), this spring drive (12) being composed of a spring (14) with two spring sections (a, bl) one spring section (bl) being formed as a rigid section the rigid section being connected to the other pliers limb (2), and the spring section (a) being connected to the adjustable leg (3), a rotation support (19) for the rigid section being provided on the other pliers leg (2) such that in the unactuated state the rigid section engages against the rotation support (19) provided on the other pliers leg (2), and in that, upon displacement of the adjustable pliers leg (3) into a mouth closing position gripping a workpiece, the rigid section comes clear of the rotation support (19) only after forced actuation with the pliers mouth jaws (5, 6) engaging against the workpiece.
22

2. Pliers as claimed in claim 1, wherein the rigid section (bl) is a link (27) at one end of which the spring element is sourced, and whose other end is rotatably disposed on the pliers limb (2).
3. Pliers as claimed in claim 1, wherein the link (27) is of paired construction and leaves a free space for the spring (14) and the spring fastening by spacing the two links (27).
4. Pliers as claimed in one of claims 1 to 3, wherein the spring section (a) is formed by a helical spring (25).
5. Pliers as claimed in claim 3 or 4, wherein the spring fastening is achieved by a carrying pin (29) which penetrates the turn packet of the spring coil (17)-and connects the links (27).
6. Pliers as claimed in one of claims 2 to 5, wherein the spring section (b) facing the rigid section (bl) of the spring (14) formed as a rotary leg spring is supported on the rigid section (b I).
7. Pliers as claimed in claim 6, wherein the support is formed by a pin (30) likewise connecting the links (27).
S. Pliers as claimed in any one of claims 1 to 7, wherein the spring (14) is
formed as a clip spring (B) with clip spring arms (33, 331) and a bend of the clip spring (3311), the clip spring arms (33, 331) or the bend of the clip spring (3311) being rotatably supported on one pliers leg (2) by means of the positioned rigid section (bl).
9. Pliers as claimed in claim 8, wherein the clip spring arms (33, 331) are
rotatably supported on a rigid section (bl) or a pliers leg (2 or 3) via different axis fo rotation (151, 1511, 161, 1611).
23

10. Pliers as claimed in either of claims 8 and 9, wherein the clip spring arms (33, 331) are formed to be of different lengths.
11. Pliers as claimed in one of claims 8 to 10, wherein the clip spring arms (33, 331) have a curved profile.
12. Pliers as claimed in claim 11, wherein the curve is concave facing the pliers mouth (M).
13. Pliers as claimed in one of claims 8 to 12, wherein the bend of the clip spring (3311) is U-shaped.
14. Pliers as claimed in one of claims 8 to 12, wherein the bend of the clip spring (3311) is helical.
15. Pliers as claimed in one of claims 1 to 14, wherein a stop (42) cooperating with the spring (14) in the expanded position of the spring drive (12) is provided on the rigid section (bl).
Dated this the 2nd day of March, 2001.

■P H

Documents:

abstract1.jpg

in-pct-2001-00245-mum-abstract(20-6-2005).pdf

in-pct-2001-00245-mum-cancelled pages(20-6-2005).pdf

in-pct-2001-00245-mum-claims(granted)-(20-6-2005).doc

in-pct-2001-00245-mum-claims(granted)-(20-6-2005).pdf

in-pct-2001-00245-mum-correspondence(17-6-2005).pdf

in-pct-2001-00245-mum-correspondence(ipo)-(23-6-2004).pdf

in-pct-2001-00245-mum-drawing(20-6-2005).pdf

in-pct-2001-00245-mum-form 1(2-3-2001).pdf

in-pct-2001-00245-mum-form 19(1-4-2004).pdf

in-pct-2001-00245-mum-form 1a(20-6-2005).pdf

in-pct-2001-00245-mum-form 2(granted)-(20-6-2005).doc

in-pct-2001-00245-mum-form 2(granted)-(20-6-2005).pdf

in-pct-2001-00245-mum-form 3(2-3-2001).pdf

in-pct-2001-00245-mum-form 3(20-6-2005).pdf

in-pct-2001-00245-mum-form 5(2-3-2001).pdf

in-pct-2001-00245-mum-form-pct-isa-210(2-3-2001).pdf

in-pct-2001-00245-mum-other document(16-6-2005).pdf

in-pct-2001-00245-mum-petition under rule 137(20-6-2005).pdf

in-pct-2001-00245-mum-petition under rule 138(20-6-2005).pdf

in-pct-2001-00245-mum-power of authority(20-2-2001).pdf

in-pct-2001-00245-mum-power of authority(20-6-2005).pdf

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Patent Number

210387

Indian Patent Application Number

IN/PCT/2001/00245/MUM

PG Journal Number

41/2007

Publication Date

12-Oct-2007

Grant Date

03-Oct-2007

Date of Filing

02-Mar-2001

Name of Patentee

KNIPEX-WERK C GUSTAV PUTSCH

Applicant Address

OBERKAMPER STRASSE 13, D-42349 WUPPERTAL,

Inventors:

#	Inventor's Name	Inventor's Address
1	RALF PUTSCH	HASTENER STRASSE 140, D-42349 WUPPERTAL,
2	KARL PUTSCH	RENNBAUMER STRASSE 70, D-42349 WUPPERTAL,

PCT International Classification Number

B25B7/10 B25B7/04

PCT International Application Number

PCT/EP99/06560

PCT International Filing date

1999-09-07

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	199 40 485.2	1999-08-26	Germany
2	198 40 741.6	1998-09-07	Germany